Fluid motor



tenteol dan.. Zi, i923.

lait-@39 ELT/IER G. GAR'LIN, OF CLAREMONT, NEWvHAMFSHIRE, ASSGNOR `T0 SULLQIVAN TdACHl-TERY COMPANY, 0F CLAREMONT, NEl/V HAMPSHRE, A CORPORATION OF IJIASSACHUSETTS.

FLD MOTOR.

Application filed January 14, 1916, Serial No. `72,164. Renewed July 18, 1921. Serial No. 485,790.

Be it -mown that l, Emmi: G. GAn'riN, a citizen of the United States, and a resident of Claremont, county of Sullivan, State of New Hampshire whose post-office address is Claremont, New fiampshirel, have invented an .improvement in Fluid Motors, of which the following description, in connection with the. accoi'npanying drawings, is a specification, like characters on the drawings repre-A senting like parts.

rThis invention pertains to improvements in direct acting fluid motors for use in rock drills or other percussive tools, and particularly, though not exclusively, to valveless percussive iiuid motors for use in hammer drills and the like.

l preferred Construction of one embodiment of my invention is shown in the drawings and herein described for illustrative purpose, while the scope'of my invention is more particularly pointed out in the appended claims. l

ln the drawings: I

Figures 1 and 2 are partial longitudinal sections on the lines 1 1 of 3 of a preferred construction of the fluid motor of a hammer drill illustrative of one embodiment drill steel rotating means 12., pressure fluid feeding means and coordinated controlling mechanism, which parts may be of.' any suitable construction. and arrangement and, speifically. oonilltitute no part of the present invention.

Pressure fluid is supplied to the fluid inotor from any suitable source through a supply conduit 13 preferably opening into the smaller piston chamber 8 through a port 14e which is preferably so located yas to co'nneet at one extremity of the piston Stroke with 'a' `grooved portion 15er the piston and adapted to ad 'it Apressure 'fluid to the intermediate pressure receiving aree. 16of the piston head 9. l preferably provide afby-pass port 17 to conduct pressure fluid to and from the small piston chamber 8,`preferably at the rear end thereof as shown, to act on the pressure receiving area 18 to assist in impelling the pistoirforwa-rd on its forward stroke. The forward point of communication of this by-pass port with t-he bore 8 is so disposed relative to the inlet port lil that the latteris con- -nected `with the chamber 7 before, and resure receiving area 19, and to this end l may provide areturn passage 2O adapted to conduct fluid from the rear pressure fluid supply port 13 to the enlarged piston chamber l;

.i preferably provide pressure fluid inlet means 20 adapted to admit pressure fluid to a groove 21 when the piston 1s approaching y the forward limit of its stroke, so that live pressure fluid can be supplied to the return pressure receiving area through the return port 20. This pressure fluid inlet means may if desired be combined. with'the inlet le: by an elongation thereof. l may supply a single exhaust port 21 to exhaust fluid from both pressure receiving areas of the piston head 9.

When my invention is used in connection with a hammer drill l prefer to interpose a. striking plug of a well-known type between the percussive piston andthe drill steel 11. As shown in Figures 3 and 4. I

prefer to use plural by-pass ports 17, re-

turn ports 20, and exhaust ports 21.

`The embodiment 0f my invention illustrated, operates as follows: Assuming the piston to be in the position shown in Fig.

1, pressure fluid admitted through the supply port 14 passes around the reduced portion 1 5 ofthe piston and acts upon the intermediate pressure receiving area 16 to impel the piston forward. A Asmall quantity of pressure fluid also passes through the port 23 into the by-pass port 17 and thence,

fter the initial forwardlmovement of thepiston, into the smaller pistonv'chamloer 8 to prevent the formationof a vacuum in said piston chamber, and also, to some eX- assist in driving the piston forward. After tent, to act upon the pressure area 18 to the piston has advanced a portion of its stroke, the supply ports 14- and 23, are closed by the piston head 10, and the piston completes its working stroke by the expansive action ofthe pressure fluid. When the piston has nearly completed its forward stroke,

live pressure fluid is admitted to the front ot the piston to act on the pressure area 19 to return the piston. l prefer to admit such lluidinto the piston Lgroove -2 through the port 20, and to conduct it to the piston'chamber Y tirough the return port 20, all as shown in 2.. At this time the air trapped in the` pistoia chamber by the coveringl of the port 23 by the piston portion 10 is so fully expanded asto exert only a negligiblepressureon` thepiston surface 18, which pressure is much'morezthan overcome by the live pressurev acting onfthev greater piston area 19. After the' return stroke has been started, the ports 20 and 2O are closed by the piston head1() and the,

returnstrolre is completed by the expansive force or the pressure fluid in the piston chamber 7, until the position shownin Fig. 1 is attained, afte'rwhich the. whole operation is repeated as described. As thepis ton approaches the limit of its rearward stroke. thertrappedair in the piston chamber 8 isl again compressechthereby cushion.- ing said strolzeg and when the port; 23 is again uncovered by the piston portion 10', lsaid air will have been compressed to substantially itsoriginal extent, balancing the large ports-,all of which-:contribute tofvthe. rapid, eflicienti and economical: operation ofi thetool.; In the construction i illustrated 'the pressurefluidadmitted;- to thewchamben 7 doesf not act upon thexpressure area 18- of thepiston head 10 asin my copendingVV application filed lam 111 1.916,3; lerialy No.2 This effects a saving' in pressure Huid anilpermits -meto retl "nr-the'piston derstood-lL theft` changes; involving reversal .ofi el departingfrore therseepeeot nue-invent 1" preferably without thel resistancocf livefair pressures opposing pressure surface;euntilzthei limit ofiA the ,freturn-..strolre nearly'.V reached; f

llhile :l have-.shown and described-` onev embodimentu ofV myv invention;Y it*- willbeeuns f omissiema. substitution, alteration, rearrangementfor`- lents, 1 maygbemaderfwitliout;

`cond .Y mediator,pressure?chambers;. tl v My invention and what l desire by Letters atent to procure is defined in the `following claims:

1. A valveless percussive fluid motor comprising,` in combination, a cylinder of two inside diameters; a piston of two outside diameters therefor, said piston presenting a. plurality of pressure areas effective to receive pressure to move said piston in one direction and a single pressure area effective to receive pressure to move said piston in the opposite direction; live pressure fluid supply means; and piston controlled pressureliuid distributing` means effective to supply live pressure liuid to said single pressure area while withholdinp,` live pressure fluid from said plurality of pressure areas and closing communication between said' last namedv areas. n

2.. A valveless percuss-ive fluid motor-*compris-ing,.in combination, a cylinder oit two diameters; a piston of two diameters therefor; said kcylinder and piston presenting a i plurality of pressure chambers effective to receive pressure fluid to move said piston in one direction and-a singlepressure chamber effective to receive pressure to move said piston in the opposite direction; pressure liuidL supply means g. pressure fluid distributing` means comprising;y separate conduit means leading," to eachy of. said piston cham.- bers,eachof said conduit means being individually controlled by said piston, and a plurality of reduced portions inthe smaller diameter part of said piston intermittently effective to connect said pressure fluid supply means with said distributing. means. Y

3; A valveless percussivefluid motor com-v prising', in combination, a cylinder providing' a larq'e piston chamber and a smaller piston chamber;` a piston therefor, having' a large piston head reciprocable in said large pistonchamber, anda smallerpiston head reciprocablevin said smaller piston chamber; said cylinder and, piston providing' three pressurel receiving chambers, two of which receive pressure to actuate said piston in one directionv` and: ther third of which receives pressure to actuate said piston in the opposite direction;. and pistoncontrolled conduit means providing.forthe admission oi live pressure fluid tothe last named pressure receiving chamber. while: withholdingv live pressure-fluid :from the'other two pressure receiving chambers and closing communica.- tioiifbetween f said last. named chambers.

4f. A percussive fluid motor comprising. in combinatioma cylinderof two diameters, a piston'gof twoi diametersthercfor, said cylinder -and* piston` providing;V three pressure chambers large, small and intermediate .and pist-on V controlled pressure-fluid distributinguit means @providing` .initialI admission y'e pressurgeffiuid. to said small interoiili after; the;l

incenso admission ot live pressure tiuid to said in termediate pressure chamber' alone, and the subsequent admission of live pressure lluid to said large pressure chamber While \vi th. holding live pressure fluid from said small and intermediate pressure chambers.

5. u valveless percussive fluid motor comprising, in combination, a cylinder providing a large piston chamber and a smaller :iiston chamber' a iston .therefor havin@Vv live pressure fluid to the lastnamed pres-v sure receivingchamber, said last named piston controlled conduit means being` inde-` pendent of said first named conduit means.

6. .A valveless'lpeicussive fluid motor piston controlled comprising', in combination, a cylinder providingy a large piston chamber and .a smaller piston chamber; a piston therefor having a laro'e piston head reciprocable in said large piston chamber and asmaller piston head reciprocalin said smaller piston chamber, intermediate piston portion intermediate said large head and said smaller head and fitting said smaller piston chamber; pressure conducting; reduced piston portion between said intermediate piston portion and said larger head; a pressure coi'iducting` reduced piston portion between said interme4 di e portion and said smaller piston head; iuid inlet means; port means a ternately opened to said lluid inlet means by said pressure conducting` reduced piston portions respectively and closed to live pressure luid by said intermediatepiston portion, Whereby pressure fluid is alternately admitted to oppositely effective pressure surfaces of said iarrfer piston bead to produce reciprocating nzoif'onieut oil said. piston; and separate port means to conduct pressure to said smaller pistou head dui-inn' admission `to the adjacent side o l' said larpger head, said last mentioned port means beings; closed at all other times by said intermediate piston. porlion.

sure elifective to receive pressure to e direction; separate piston con` l. A peicussive luid motor coinpi'isiiig,v

move said piston in the opposite direction',

live pressure 'fluid supply means, and prese sure fluid distributingjmeans etlective to supply live pressure liuid to saidpluralityl of pressure areas vand to close communie: tion between them. p

8. A valveless. percussive :fluid motor Icomprising, in combination, a cylinderol" 'tivo diameters; a piston oittyvo dian'ietei's'therefor; said cylinder and piston presenting a plurality'of piston chambers ei'i'ective to"re-' ceive pressure fluid to .move 'said piston 'in one direction anda single pressure chamber effective to receive vpressure to move said piston in the opposite direction; pressure" liuid supply means including separatepis-` ton controlled conduit means for adroittinel Vhuid to said piston chambers; pressureluid distributing means; and a plurality oi2 vre` duced portions ina smaller diameter part ol said piston' intermittently ellectivelto con ne lt said pressure fluidV supplymeans ivitliv id distributing means, said reduced por' tions controlling` separate'liuid inlets, iespectively.

9, A valveless percussivelluid motor com- `prising, in combination,l a cylinder of tvvo diameters, a piston of tivodiameters there lfor, said cylinder and rpiston presenting` a'l j plurality or' piston chambers eii'ective to receive fluid pressure to move said piston in one direction and a single pressure chamber 'piston in the opposite direction, presser fluid inlet means, separate conduit means' leading to each of said piston chambers, the connection of each of said lconduitmeaifisv with said inlet means being individually controlled by the piston toelect expansiva action or the pressure `fluid in each of said pressure chambers and to close comiiiiunica- I tion between all of said chamber except during their connection With the inlet mea-ns. 10A valveless percussive fluid motor comprising, in combination, a cylinder pro-,i

vi ding a large piston chamber and a smaller piston chamber, a piston therefor having` a large piston head reciprocable in said' largeV piston chamber and a smaller piston head vreciprocable in said lsmaller piston chamduced piston portion between said inter-me# diate portion and said smaller piston head,

Aeffective to receive pressure to move' said l rio lluid inlet means, port vmeans alternately opened to communication with saidy fluid portion whereby pressure duid i'svalternately admitted to oppositely effective surfaces of isol said larger pisse-ii head ro produce reciprocatng nieren e L pl i' i rate port leai Lnb# o seid sinalle and opened by said i'irsl; n iedi ton port-ion communicate xvii-li s i means and Willi lie adjacenj side larger head duringl dinissionfljo llie latter and closed al, all @Mier limes b v said intermediate piszen por on.

ll. A valveless fluid operated motor coniprisingI a cylindega piston vtherein having; a pair. of pressure receiving adapted to receive pressure ie eifel the stro-lies in one direction and a. single pressure reeeiving area to receive pressure to eii'ecthe opposite strokes, fluid distribution ineens operative to supply live pressure continueuslv frein the vbeginning` oi said n l nieiiliie 'e strokes dilerenr proper fraciional puf- 1rions of such strokes lo seid iair or pressure receiving areas respeciv ly, und ineans for admitting pressure inen- 'ro zhe ihiri tioned pressurereceiving,1 lo effect said second menbioned slorelres. 12. A valveless uid operaeed motor eoiiiprising' cylinder, a. piston therein liavii'iga pair of pressure receiving areas adapted to yreceive pressure io eiiecl; a stroke in one dif rection and a single pressure recoivingarea `to eect the opposie ssrole, ineens for adinitting live pressure to said pair pressure receiving1 areas roni Jolie beginning of and for respectively different fractional portions 'of said first ineniioned stroke, ineans l'or directly exhausting' the pressure acting; upon bul; one of the pressure areas, and means for admitting` live pressure "lo 'lie third *i reniioiied pressure reeeiving' area to ellieet a return stroke.

13. A i'luid operated motor comprising, in combination, a cylinder, a pistonl therein having a pair of pressure receiving adap'ed lo receive pressure io eilectllie stroke in one direeion, one of said aiciis being materially larger than the eelieiglaiid a single.pressure-receiving.area to receive pressure io eiliiect ,the opposite stroke, ineansV operative to coniiecf said pair of pressure receivingareasfiviL-h inlet pressurelroin Jdie beginning ofaiid' 'for different' proper frac-1 tional porLioiis;respectively or the strokes in one direction, ineaiis'iorl exhausting tlieiluid which is actinguponthe larger of said areasadjaeent the lend of the stroke in that direi:- tion, and ineans for supplying and exhausting`Y vpressure fluid to ao upon the third )oriions or' the slrolre'in one direction means l'or exhausting the fluidivhich acts upon 'the larger of saidv areas adgacent the end of lhe stroke, and means vor supplyingy and ezilia-ustiiio" pressure iluid to act upon the third 7 V mentioned pressure receiving area.

In testimony Whereoi', l have signed myv naine lo this specification, in the presenee of tivo subseribingA Win'esses.A

ELMER G. GillllN.

lWitnesses D, A. CABoT, i

lHnononE B. JoHANNi ressuie receiving areasv with a 

